Electronic structure and thermodynamics of V2O3 polymorphs

A metastable bixbyite-type polymorph of vanadium sesquioxide, V2O3, has recently been synthesized, and it transforms to the corundum-type phase at temperatures around 550 degrees C. The possibility of a paramagnetic to canted antiferromagnetic or even spin-glass-like transition has been discussed. Quantum-chemical calculations on the density-functional theory level including explicit electronic correlation confirm the metastability as well as the semiconducting behavior of the material and predict that the bixbyite-type structure is about 0.1 eV less stable than the well-known corundum-type phase. Nonetheless, quasiharmonic phonon calculations manifest that bixbyite-type vanadium sesquioxide is a dynamically stable compound. Other possible V2O3 polymorphs are shown to be even less suitable candidates for the composition V2O3. (c) 2012 Wiley Periodicals, Inc.